EU revokes one of the patents on Biogen blockbuster Tecfidera

Biogen ($BIIB) has faced a number of challenges to its top-selling drug, multiple sclerosis med Tecfidera, in the few years since it has been on the market. Now it faces a new one in Europe in the always treacherous and uncertain realm of pharma patent law.

The opposition division of Europe's patent office Thursday revoked a method of use patent, one of four patents covering Tecfidera, which last year had global sales of $3.64 billion, one-third of the Cambridge, MA-based company's total revenues. Biogen Director of Global Public Affairs Lindsey Smith said in an email today that just as soon as Biogen gets the written decision, an appeal will be filed.

"Once our appeal is filed, the revocation of the patent will be suspended," spokesman Smith said.

She pointed out that the ruling has no effect the drugmaker's U.S. patents or even Biogen's ability to sell it anywhere in the world that it is approved. "We believe we have a strong IP portfolio protecting Tecfidera, which grew out of our pioneering efforts in bringing this important medicine to patients, and intend to defend this portfolio."

An appeal could actually hold up any threat in Europe for up to four years, Cowen & Co. analyst Eric Schmidt told investors in a note, according to Investor's Business Daily. But if it loses the appeal, Schmidt figures up to $1 billion in sales would be in jeopardy.

Tecfidera was approved in April 2013, hitting the market behind Novartis' ($NVS) Gilenya and Sanofi's ($SNY) Aubagio but quickly surpassing them in sales. Then in October 2014, Biogen reported the death of a Tecfidera patient suffering from progressive multifocal leukoencephalopathy (PML), a rare brain infection. After the FDA added that information to the drug's official label, sales of the drug lost momentum.

As sales flagged during 2015, Biogen CEO George Scangos acted. The company cut its forecast last year, cut loose commercial chief Tony Kingsley, then cut 800 jobs to find the money it needed for a new education and marketing campaign. The cost savings and stepped-up marketing appeared to kick in as the company had hoped. Sales in Q4 were up 16% to $993 million, helping boost full-year revenue 19% for Tecfidera to $3.64 billion.

- read the Investor's Business Daily story

Special Report: The top 20 drugs in 2020--worldwide sales - 9. Tecfidera